package yt.spider.adapter;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;

/**
 * Created by 小呆呆 on 2018/1/18.
 * 设置RecyclerView分割线
 */

public class MyItemDecoration extends RecyclerView.ItemDecoration {
    private static final  int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };
    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
    private Drawable mDivider;
    private int mOrientation;
    public MyItemDecoration(Context context,int orientation){
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

    public void setOrientation(int orientation){
        if(orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST){
            throw new IllegalArgumentException("无效方向");
        }
        mOrientation = orientation;
    }

    public void onDraw(Canvas c,RecyclerView parent){
        if(mOrientation == VERTICAL_LIST){
            drawVertical(c,parent);
        }else{
            drawHorizontal(c,parent);
        }
    }

    //画竖线
    public void drawVertical(Canvas c,RecyclerView parent){
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();
        final int childCount = parent.getChildCount();
        for (int i=0; i<childCount; i++){
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)child.getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final  int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    //画横线
    public void drawHorizontal(Canvas c,RecyclerView parent){
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();
        final int childCount = parent.getChildCount();
        for (int i=0; i<childCount; i++){
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)child.getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final  int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent){
        if(mOrientation == VERTICAL_LIST){
            //画横线，就是往下偏移一个分割线的高度
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        }else{
            //画竖线，就是往右偏移一个分割线的高度
            outRect.set(0, 0, 0, mDivider.getIntrinsicWidth());
        }
    }
}
